Other Amusing Claims and Tidbits

As I go through all of the various sellers websites, I come across some interesting claims. Practically everyone claims to be the first, the biggest, the best, the only LED grow light company you can really trust. Not unexpected, right? Some claims are neither good or bad but worth pointing out as they may affect how you grow. But, there were some claims that went beyond the pale and really amused me, and some are outright lies.

Cooling Fans: Good or Bad

Several LED grow light companies claim that cooling fans which provide active cooling in LED light fixtures are a bad thing, but I don't believe there is a clear case against fans. I've tried quite a few LED grow lights and it is certainly true that many fixtures are plagued with cheap, noisy, poor-quality fans prone to early failure. Higher-quality, quiet and reliable fans are certainly available and some LED grow lights use these fans. There are advantages and disadvantages to an LED grow light having active cooling fans- a trade-off between lifespan/efficiency and noise/reliability.

LED's enemy is heat: the cooler they run, the more efficiently they put out light, and if the diode gets too warm it causes permanent damage and decreases the amount of light it produces from then on. Keeping LEDs cool is the key to keeping them as bright as possible for as long as possible. The LED bulbs you buy at Home Depot are fairly low-power (and therefore low-heat) and can stay bright without a fancy cooling system, although many feature small metal fins (a "heat sink") to help cool them off. For the increased lighting power required with grow lighting, better cooling is crucial.

There are tricks to keep LEDs cool– running them at a fraction of their rated current/wattage (called "under-driving") helps, but when you get enough LEDs in one area to produce enough light to grow plants, some sort of heat-conductive "heat sink" is required. There are several different kinds:

Fanless, passive heat sinks rely on the convection properties of air to help cool them. Increasing the surface area – usually by adding "fins" – helps to increase the heat dissipation, but there are limits to the heat (/power) density they can handle due to limits on how quickly air flows through the fins on its own, so these are typically very large with low power density.

Fanless, heat pipe heat sinks employ pipes full of a liquid that evaporates and condenses at just the right temperatures to move heat away from the LEDs to a remote finned heat sink above the LEDs. This allows LEDs to be driven harder and/or placed more closely together, but requires an even larger total surface area for the heat sink due to inefficiencies in heat transfer. Most designs I've seen dramatically increase the vertical size of the light fixture, often causing problems in height-limited environments typical of indoor growing.

Active cooling heat sinks utilize one or more fans to move cool air across a finned heat sink of either of the above 2 types, increasing the total cooling. This either keeps things cooler to keep the LEDs brighter for longer, decreases the size of the fixture, or both. Depending on the design, multiple fans can provide redundancy to eliminate issues with possible fan failures, though it mostly comes down to the quality of fans used how reliable this is.

Each type can work well, and each type can be overloaded with a heat load it can't dissipate if the fixture is designed poorly, or if the heat sink becomes blocked for some reason.

There is no perfect solution; fans offer better cooling and should keep the LEDs brighter and more efficient for longer, but can fail or be noisy, especially if they're cheap. In a passively-cooled LED grow light you will be able to keep the LEDs cooler and running more efficiently (brighter for the same power input) and last longer by aiming a fan at the passive cooling fins- so why not do it as part of the light fixture?

LED Expected Output After 50,000 Hours > 90%

In California Light Works' product spec sheets for all of their lights, they boldly claim that their LEDs will have more than 90% of their original output after 50,000 hours. If you were running the lights 24 hours per day, that would be 5.7 years before they dimmed by 10%; at 12 hours per day, this means they would still be putting out 90% of their original light after 11.4 years! Sound too good to be true? It probably is.

Unfortunately, a quick check of specification sheets for the top LED manufacturers shows that this is almost certainly a lie. The boldest claim I found from any actual LED diode manufacturer was that their diodes would have 70% of their original brightness after 65,000 hours in ideal (cool) conditions. Most diode manufacturers only claim 70% of the original brightness after 50,000 hours in ideal conditions.

Even if California Light Works is using the best LEDs on the market for longevity and managing to keep them very, very cool, at 50,000 hours even these LEDs would have only 77% of their original brightness. There is just no way that after 50,000 hours (a minimum of 5.7 years if the lights are run 24/7!) the Solar Storm or Solar Flare series of lights will have more than 90% of their original output. As awesome as LEDs are, they still fade with time, and fade or fail faster if run at high currents and in warmer tempearatures such as in grow lights. With current technology as I understand it, there is simply no way that any LED grow light bright enough to grow and flower plants such as Cannabis will have more than 77% of it's original brightness after 50,000 hours. California Light Works is lying about how bright their lights will be over time; even my own tests with my simple light meter show they degrade much faster.

Lifetime 100,000 Hours or More

Mars Hydro claims Mars … series grow lights are rated at 100,000 hours of use or more. The Mars lights are made with Epistar or Cree LEDs, and considering that Epistar and Cree themselves say the LEDs will be at 70% of their original output after 50,000 hours (if they're kept cool), it seems that Mars Hydro is stretching more than a bit with this claim. After 100,000 hours of use (11.4 years constantly on, 22.8 years on 12/12)– the LEDs may still light up (barely), but you're not going to be growing any plants with them. Perhaps they consider "acting as a paperweight" a "use"?

1W or 3W LEDs Are the Most Efficient

Many companies claim that whatever LED chip set they chose is the most efficient, and that their competitors are using the less-efficient LEDs. As they add new lights to their lineup with larger LED diodes, they have to go through their site and remove these old claims. Pro Source Worldwide still has at least one page claiming 3W LEDs are bad compared to 1W LEDs, but they recently upgraded their entire product line to use solely 3W LEDs.

A lot of companies featured on here still claim that 3W LEDs are best, with Hydro Grow even going so far as to say Companies selling LED Grow Lights with 5W LEDs are preying on the uneducated consumer who doesn't realize that more power consumed doesn't equate to more light output with 5W LED Grow Lights. It is for this reason Hydro Grow uses 3W LEDs in all X-PRO LED Grow Lights to ensure the highest output with the least power consumed. This is fairly misleading, as they aren't giving you all the relevant information.

Yes, 3W LEDs are more efficient than 5W LEDs; the less wattage that's run through an LED, the more efficient it is. 1W LEDs are even more efficient than 3W LEDs, but 1W LEDs aren't really bright enough to grow most plants with, so they are slowly fading from the LED grow light market. 3W LEDs will probably follow soon because even though they are more efficient than 5W LEDs, by the time you add secondary lenses to make them intense enough to grow taller or high-light plants, you lose this extra efficiency. If this weren't the case, Hydro Grow would be putting the even-more efficient 1W diodes in their lights with a secondary lens to ensure the highest output with the least power consumed.

I'm not saying 5W diodes are better than 3W, just that they aren't necessarily less efficient at growing plants. Once 10W LEDs come out in colors other than blue and white, it will be interesting to see if they prove to be better at growing plants or if the decreased efficiency isn't worth it. We probably have a few years to wait on lights actually using 10W diodes as intended though; so far the grow lights that include 10W LEDs are still running them at even less power than their mixture of 3W and 5W LEDs. An all-10W, all-white grow light doesn't excite me much either; I've yet to see or hear of an all-white LED perform as well as the proper discrete colors.

Either way they state it, it is a lie– their white LEDs are blue LEDs, covered with a phosphor to convert some of the blue photons into other colors. This inherently involves a 10-30% loss of photons (intensity / flux density) due to the nature of phosphors, and an even-larger loss of total light energy.

Rami Vardi, the owner of Spectrum King, has previously gone on record saying that plants prefer red and blue light as a spokesperson for his now-dead previous LED grow light company, Stealth Grow. He may have changed his mind in the last few years, but he can't defy physics and make a white LED have more photon flux than the blue LED at its base. For "luminous flux", which is based on the yellow-weighted human-eye sensitivity lumen standard, the white LEDs will always win because they are mostly yellow light- but for radiant flux, PAR, flux density, intensity or simple photon count, a blue LED will always win over the exact same blue LED with a phosphor coating to make it a white LED.

Spectrum King made a video where they take a red, blue and white LED and measure the PAR and Lux (yellow-weighted, human-eye response lumens per square meter) reading from each, to show that their white LEDs are brighter. Unfortunately they are not comparing equal LEDs; they even admit as much in the video, saying that the blue LED they are testing is comprised of more (but smaller and less-efficient, though they don't say so) chips than the white LED they are testing. Notice how the white / "full spectrum" LED they test is mounted to a large cooling plate (known in the industry as a "star board") while the red and blue LEDs they test aren't? LEDs degrade with heat; the red and blue LEDs they test are of unknown age, make and technology, but they aren't being cooled as effectively as the "full spectrum" white LED they are testing, which means (even if they were of equivalent age / technology) that they would be degrading much faster. In addition, the manufacturer of the PAR meter they are using warns that it under-reports the intensity of blue LEDs and even that LEDs that output a large proportion of radiation above approximately 660 nm will read very low and should not be measured with an Apogee quantum sensor/meter (the Sun System PAR meter they use in the video is just a re-branded Apogee meter). If the red LED Spectrum King is testing is a 660nm diode, it completely explains the low PAR reading for it.

They aren't comparing apples to apples in the video and they aren't using an appropriate PAR meter; if they were, the "white" LED would have 10-40% less PAR than the blue LED, since the "white" LED is a blue LED with a PAR-degrading (but lumen / Lux enhancing) phosphor coating. Spectrum King is deliberately distorting their statements and demonstrations to try and trick you into buying one of their lights, and not just on this issue.

Need Yellow Light or to Run Your Grow 10 Degrees Warmer

Black Dog claims that to maximize yield with their grow lights you need to keep your growing area 10 °F warmer than you would with traditional HID lighting and even some other LED grow lights. They do provide a lot of thermal pictures showing leaf temperatures to make their case, and argue that yellow light is responsible for heating plants' leaves- so by reducing the amount of yellow light you can cool your grow less.

Black Dog suggests that you just run the room warmer and save the electricity creating the yellow light to start with, and save on cooling / ventilation. Spectrum King is arguing that you need to create the yellow light to warm the plants up–but then you need to ventilate or run air conditioning more to keep them from overheating. Black Dog's approach certainly seems much more energy-efficient, and though it goes against all traditional advice to flower at 85 °F, my personal experience over the past year is that it works great.

California Lightworks and Pro Source Worldwide also recommend running 10 °F warmer with their LEDs, California Lightworks claims this is necessary since their lights don't give off any IR. Pro Source Worldwide doesn't provide any reasoning that I can find.